As of 1959, different techniques of Nuclear Magnetic Resonance (NMR) were being developed with respect to noninvasive, in-vivo methods for the observation and measurement of physiological processes and for diagnostics, for example, relating to hemodynamics. In 1968, NMR was for the first time applied to study the structure of intracellular water and the metabolism of cells; observations on extravasal water in myocardial and pulmonary tissue have been described in the study of cardiac infarction and pneumonoederma and a feasibility study for the diagnosis of ischemia has been reported. In 1971, application of NMR to cancer-research was initiated. Finally, in 1973 the development of various NMR-tomographic imaging processes, designated zeugmatography was originated. An article in "Nature", Vol. 270, p. 722 (1977) describes the achievement of a spatial resolution of 0.4.times.0.4.times.3.0 mm.sup.3. An X-ray computer tomogram of a human head is depicted in "Physics Today", Vol. 30/12, p. 32, December 1977. The NMR-zeugmatogram through a human radiocarpal joint, published simultaneous in the aforesaid article in "Nature" demonstrate comparable image qualities. Nevertheless about 100-times as much time (about 9 minutes) was required to accumulate the data for the latter.
One serious handicap of the above NMR-methods derives from having to take data at a signal-to-noise ratio much too close to one. Simultaneously, the observed volume has to encompass a much too large region of the sample for detailed and differentiated measurements. The described results may only be obtained by data accumulation and signal averaging techniques requiring an appreciable amount of time. A further uncertainty in the data during its accumulation is produced by a slightly shifting of the sample in reference to the observed control volume, due to involuntary movements, for instance, created by cardiac action or respiratory movement or the like. That all adds up to the described disadvantages of having to abserve in much too large regions of the sample and of requiring time-consuming techniques for multiple data accumulation and signal averaging.
The radiation exposure of the patient quite often approaches the range of permanent damage (radiation entrance dose .gtorsim.3 rad) during examination involving X-rays, angiography, computertomography or nuclear medical diagnostics. This constitutes a serious obstacle in utilizing these methods for medical check-ups, for screening and even for the validation of the course of therapeutic measures.